This is the fourth ACTIVE thread that's talking about battery registration right now, wtf? Here's a copy/paste of the post I've already put in the other 3:

"Registering" is the process of informing the computer that a new battery has been installed, and while failing to do that won't prevent the new battery from working, it IS good to do and CAN make a difference in how the car manages the new battery and how long the new battery lasts. Dealers will definitely overcharge on labor for registration, because if you have a coding cable and the right software the process takes all of 60 seconds. There are DIY threads on this forum showing how to do this.

As for what exactly registering a battery does, the link I added at the bottom of the post shows a description of the process. Registering basically allows the computer to pull the proper amount of current from the battery and manage it properly, which it might not do if it thinks it's still dealing with an old battery.

I had first-hand experience with what happens when you don't register a battery recently with my wife's car. Her Mini Cooper S's moonroof would only close completely while the engine was running; when only the ignition was on, it would come forward but wouldn't pull itself all the way down to make the seal, and it moved much more slowly overall. I suspected the battery wasn't providing enough power, so we got a new one. The indy shop didn't have access to the computer they normally used to register batteries that day, so I told them to give me the car with just the battery and I'd DIY it. I tested the moonroof with the new battery BEFORE registering, and the problem remained, which I suspected was because the computer didn't know it could now pull more current from the battery. Registered the new battery, problem solved immediately.

Also depends on the color of the battery your car came with. Some dont need to be registered... I belive WHITE dont need to and BLACKs do. Correct me If I am wrong...

You're wrong. White vs black is non-AGM vs AGM batteries. BMW has a doc that I can't find right now outlining when each model started requiring battery registrations, but it's pretty much every car produced from 2006 onward.